GLUTAMINE AND ALPHA-KETOGLUTARATE PREVENT THE DECREASE IN MUSCLE FREEGLUTAMINE CONCENTRATION AND INFLUENCE PROTEIN-SYNTHESIS AFTER TOTAL HIP-REPLACEMENT

After surgical trauma, protein synthesis, as well as the concentration of free glutamine in muscle, decreases. Total parenteral nutrition (T PN) alone does not prevent the decrease of glutamine in muscle, but TP N supplemented with glutamine or its precursor, a-ketoglutarate, maint ains amino acid concentration in muscle and preserves protein synthesi s, The aim of this study was to characterize a human trauma model usin g patients undergoing total hip replacement, and furthermore to invest igate whether glutamine or a-ketoglutarate alone without TPN can preve nt the postoperative decrease in muscle free glutamine. Metabolically healthy patients undergoing total hip replacement were randomized into three groups. The control group (n = 13) received glucose 2 g/kg body weight (BW) during surgery and the first 24 postoperative hours. The glutamine group (n = 10) received glucose 2 g/kg BW and glutamine 0.28 g/kg BW, and the alpha-ketoglutarate group in = 10) received glucose 2 g/kg BW and alpha-ketoglutarate 0.28 g/kg BW. Muscle biopsies were p erformed before surgery and 24 hours postoperatively. Free glutamine c oncentration in muscle decreased from 11.62 +/- 0.67 to 9.80 +/- 0.36 mmol/kg wet weight in the control group (P < .01), whereas it remained unchanged in both the glutamine group and alpha-ketoglutarate group. Protein synthesis, as reflected by the concentration of total ribosome s, decreased significantly in the control group, but not in glutamine and alpha-ketoglutarate groups, Polyribosome concentration decreased s ignificantly in both the control and alpha-ketoglutarate groups. Total hip replacement can be used as a reproducible trauma model, with char acteristic changes in the muscle amino acid pattern and protein synthe sis 24 hours postoperatively. Glutamine, as well as cu-ketoglutarate, attenuated the decrease in free amino acids in muscle tissue after sur gical trauma during hypocaloric infusion of glucose. Copyright (C) 199 5 by W.B. Saunders Company